04._Geotech_Rpt_230815.pdf

August 15, 2023

FILE NO.: 305727‐001

Mr. John Evans, PE Cannon 1050 Southwood Drive San Luis Obispo, CA 93401

PROJECT: CAMP SAN LUIS OBISPO

RANGE ROADS PAVEMENT REHABILITATION

SAN LUIS OBISPO, CALIFORNIA

SUBJECT: Geotechnical Recommendations for Roadway Rehabilitation

REF: Proposal for Subsurface Exploration, Pavement Assessment and Roadway Rehabilitation Recommendations, by Earth Systems, Doc. No. SLO‐2211‐ 002.PRP, dated November 2, 2022

Dear Mr. Evans:

In accordance with your authorization of the above referenced proposal, geotechnical recommendations have been prepared for the rehabilitation of the existing asphalt concrete (AC) roadways of portions of San Benito Road and Range Road at Camp San Luis Obispo (Camp SLO).

SCOPE OF SERVICES

Our scope of services for this project was to core the existing roadway, measure the existing AC and base sections and identify and sample the subgrade for the purpose of providing roadway rehabilitation recommendations. Laboratory testing to determine chemical stabilization recommendations was also performed. Subgrade samples were submitted to our laboratory for

R‐value testing, or resistance to deformation under repeated loading (ASTM D2844/D2844‐13).

Asphalt concrete and base thicknesses were recorded and are reported herein. Field reconnaissance and laboratory test data were then analyzed in the development of geotechnical recommendations for the project. Pavement section recommendations are presented in this report.

The two segments of roadway to be rehabilitated are San Benito Road, from Santa Clara Road to

Range Road, and Range Road from approximately 1,500 feet east of the intersection of Dairy

Creek Road and Pennington Creek Road to the boundary at the California Men’s Colony property line.

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305727‐001 2 2308‐043.RPT

EXISTING CONDITIONS – SAN BENITO ROAD

The portion of San Benito Road evaluated for rehabilitation is approximately 6,000 linear feet in length, 22 feet in width, oriented roughly north‐south and has an elevation gain of approximately

210 feet. Generally, the road surface appears to be comprised of multiple “phases” of paving and is oxidized and aged with localized areas of base failure, indicated by alligator cracking.

FIELD INVESTIGATION AND LABORATORY TESTING – SAN BENITO ROAD

In order to discern the existing pavement section, borings were drilled in 10 locations along the roadway, approximately every 500 feet, using a 6‐inch diameter hollow‐stem auger. The locations were drilled with a Mobile B‐53 drill rig to identify existing AC and base section thickness and subgrade composition. Bulk samples of the subgrade material were obtained from auger cuttings, and the soil was classified in general accordance with the Unified Soil Classification

System and ASTM D 2488‐17. Approximate location of boring and pavement thickness/subsurface composition can be found in Table 1 below and referenced on the boring location map (Appendix A). Boring locations are presented from the intersection of San Benito

Road and Santa Clara Road northward to San Benito Road and Range Road.

LOCATION

AC

THICKNESS

(IN.)

BASE

THICKNESS (IN.)

SUBGRADE COMPOSITION

SAN BENITO ROAD

SB1 2.25 0.00 BROWN SANDY LEAN CLAY

SB2 2.50 4.00 DARK BROWN SANDY LEAN CLAY

SB3 1.50 0.00 BROWN SANDY LEAN CLAY

SB4 2.75 0.00 DARK BROWN SANDY LEAN CLAY

SB5 3.25 0.00 DARK BROWN FAT CLAY WITH SAND

SB6 3.50 0.00 BLACK FAT CLAY WITH SAND

SB7 2.00 0.00 BLACK FAT CLAY WITH SAND

SB8 1.50 0.00 BLACK FAT CLAY WITH SAND

SB9 1.50 0.00

DARK OLIVE BROWN METAVOLCANIC

BEDROCK

SB10 2.75 0.00 BROWN SANDY LEAN CLAY

Table 1: Boring locations and subsurface composition

Boring data demonstrates that the existing AC thickness is variable, and that there is nearly no aggregate base beneath the existing roadway. As previously mentioned, the existing pavement appears to have been installed in a few phases based upon visual assessment of varying surface textures, colors and visible pavement joints. The subgrade is comprised of various types of clay

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of differing stiffness. In one location, weathered bedrock of the Franciscan formation was encountered. Pavement failure is present in isolated areas on San Benito Road primarily along the edge of the travel way in the form of alligator cracking and deflection. Where the pavement is failing, failure is likely due to a combination of factors, of which lack of base support, poor drainage and oxidation are chief.

Two subgrade samples from San Benito Road were submitted to the laboratory and tested for R‐

Value, or resistance to deformation under repeated loading (ASTM D 2844/D2844M‐13). The results of the R‐Value tests yielded less than 5 in both samples, as the material extruded from the mold during testing. Laboratory test results can be found in Appendix B.

ANALYSIS AND RECOMMENDATIONS – SAN BENITO ROAD

Based upon the conditions encountered and our observations, the roadway section of San Benito

Road lacks adequate base/subgrade structure to support current and future traffic loading. With a few exceptions, there is no aggregate base beneath the existing asphalt concrete, and most of the AC sections are, by most standards, too thin for surface rehabilitation.

Due to the quality of the subgrade, lack of aggregate base and isolated areas of failure, we recommend that San Benito Road be reconstructed or heavily rehabilitated.

Reconstruction/heavy rehabilitation has numerous advantages, including addressing underlying subgrade failures and creating the opportunity to correct grading and drainage problems, as well as to properly construct a roadway reasonable design life which will also decrease long‐term costs if properly maintained. Based upon discussions with the client, chemical stabilization/full depth recycling is a possibility for rehabilitation of the roadway. Since the roadway has minimal edge constraints and will be reprofiled to improve drainage, it may be feasible for the roadway to be pulverized/graded without hauling off any excess material. If removing material is necessary, the roadway should be pulverized first, graded for material removal, and then processed and graded.

Based upon the encountered native material and existing AC, we believe reconstruction/rehabilitation could be accomplished with a few different options. Based upon discussions with the client and project owner, we understand that chemical stabilization with both lime and cement is preferred, however, additional options are also presented herein.

The first option is to pulverize and lime treat the existing roadway and then place aggregate base and HMA. Because the encountered native soils are expansive and there is very minimal existing

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base, this option would result in native material less prone to expansion and contraction and would also reduce the required aggregate base section. After pulverization and lime treatment, the roadway should be graded to facilitate proper drainage and Class 2 aggregate base should be placed and compacted on top. Based upon laboratory testing, we recommend using 5% lime by dry weight of material and pulverizing to a depth of 15 inches. After finish base grade is made, HMA should be placed on the surface. The HMA thicknesses should be the same as listed in Table

2 below. However, the aggregate base thickness may be reduced by 25percent.

A second option is to pulverize, perform both lime treatment and cement treatment of the existing roadway, and then to place HMA on the surface. Lime treatment would help to address problems caused by the native expansive soils, and subsequent cement treatment, also known as full depth reclamation with cement (FDR‐C), would replace the Class 2 aggregate base. After cement treatment is complete, HMA should be placed on the surface of the roadway. Based upon laboratory testing performed on native material, we recommend using 2% lime by dry weight of material processed to a depth of 15 inches. The lime treated material should be allowed to

“mellow” for a minimum of 72 hours prior to cement treatment. Cement treatment should then be performed following lime treatment using 2% cement by dry weight of material. The HMA thicknesses should be the same as listed in Table 2 below.

A final option is to reconstruct the roadway using conventional reconstruction methods. This would involve removing the existing roadway to subgrade depth and scarifying and recompacting the material to a minimum of 95% of maximum dry density. Class 2 aggregate base should then be placed and compacted to a minimum of 95% of maximum dry density in lifts not exceeding 6 inches. Finally, hot mix asphalt should be placed and compacted on the surface.

Below are traditional reconstruction sections for Range Road (Table 2). Determination of the appropriate Traffic Index is left to others. Calculations have been made using an R‐value of 5.

Traffic Index HMA Section (inches) Base Section (inches)

7.0 4.00 15.50

8.0 4.50 17.00

9.0 5.25 21.00

10.0 6.00 23.50 Table 2: Reconstruction sections based upon an R‐value of 5

Based upon discussions with the client and project owner, we understand that a T.I. of 10.0 is preferred. Where indicated, Class 2 aggregate base should conform to Section 26 of the 2018

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Caltrans Standard Specifications, and HMA should conform to Section 39 of the 2018 Caltrans

Standard Specifications, and should be compacted to a relative density between 92% and 97% of theoretical maximum density. Should lime treatment be chosen, it should conform to Section 24 of the 2018 Caltrans Standard Specifications, and cement treatment, or FDR‐C, should conform to Section 30 of the 2018 Caltrans Standard Specifications.

EXISTING CONDITIONS – RANGE ROAD

The portion of Range Road evaluated for rehabilitation is approximately 7,700 linear feet in length, 22 feet in width, oriented roughly east‐west and has an elevation gain of approximately

230 feet. Generally, the road surface appears to be comprised of multiple “phases” of paving and is oxidized and aged with areas of severe base failure, indicated by alligator cracking and deflection, as well as areas with lateral cracking as they are next to an unconfined slope edge.

FIELD INVESTIGATION AND LABORATORY TESTING – RANGE ROAD

In order to discern the existing pavement section, boring were drilled in 15 locations along the roadway, approximately every 500 feet, using a 6‐inch diameter hollow‐stem auger. The locations were drilled with a Mobile B‐53 drill rig to identify existing AC and base section thickness and subgrade composition. Bulk samples of the subgrade material were obtained from auger cuttings, and the soil was classified in general accordance with the Unified Soil Classification

System and ASTM D 2488‐17. Approximate location of borings and pavement thickness/subsurface composition can be found in Table 3 below and referenced on the boring location map (Appendix A). Boring locations are presented from the west end of the Range Road project limit eastward toward the property line of Camp SLO.

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LOCATION

AC

THICKNESS

(IN.)

BASE

THICKNESS

(IN.)

MISC AC

THICKNESS

(IN.)

SUBGRADE COMPOSITION

RANGE ROAD

RR1 2.25 0.00 ‐ BROWN SANDY LEAN CLAY

RR2 2.25 0.00 ‐ OLIVE BROWN METAVOLCANIC BEDROCK

RR3 2.00 0.00 ‐

BROWN SANDY LEAN CLAY + OLIVE BROWN

METAVOLCANIC ROCK

RR4 3.00 0.00 ‐ OLIVE BROWN METAVOLCANIC BEDROCK

RR5 1.75 0.00 ‐ OLIVE BROWN METAVOLCANIC BEDROCK

RR6 2.25 0.00 ‐ FAT CLAY WITH SAND

RR7 2.25 0.00 ‐

BROWN SANDY LEAN CLAY + PALE BROWN SANDY LEAN

CLAY WITH GRAVEL

RR8 2.00 1.00 3.00 REDDISH BROWN CLAYEY SAND WITH GRAVEL

RR9 2.00 0.00 ‐ REDDISH BROWN CLAYEY SAND WITH GRAVEL

RR10 1.50 1.25 4.50 BROWN SANDY LEAN CLAY

RR11 3.00 0.00 ‐ OLIVE BROWN METAVOLCANIC BEDROCK

RR12 2.25 0.00 ‐ REDDISH BROWN CLAYEY SAND WITH GRAVEL

RR13 1.25 0.00 ‐ REDDISH BROWN CLAYEY SAND WITH GRAVEL

RR14 2.00 0.00 ‐ BROWN CLAYEY SAND WITH GRAVEL + BLACK FAT CLAY

RR15 3.00 0.00 ‐ GRAYISH BROWN FAT CLAY

Table 3: Boring locations and subsurface composition

Boring data demonstrates that the existing AC thickness is variable, and that there is nearly no aggregate base beneath the existing roadway. As previously mentioned, the existing pavement appears to have been installed in a few phases based upon visual assessment of varying surface textures, colors and visible pavement joints. The subgrade is comprised of various types of clay and weathered bedrock of the Franciscan formation. Pavement failure is present in large areas on Range

Road in the form of alligator cracking and deflection, as well as along the edge of the travel way where slope movement has induced lateral cracking. Based upon the boring data, pavement failure can likely be attributed to poor/variable subgrade material composition, lack of aggregate base, poor drainage and aging.

One boring (RR7) was drilled to a depth of 20 feet below ground surface near an existing culvert that is planned for reconstruction. As part of the culvert replacement, the slope associated with the culvert will also be reconstructed. Recommendations for slope reconstruction can be found in the following section.

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Four subgrade samples were submitted to the laboratory and tested for R‐Value, or resistance to deformation under repeated loading (ASTM D 2844/D2844M‐13). The results of the R‐Value tests ranged from 3 to 11. The laboratory test results are attached in Appendix B.

ANALYSIS AND RECOMMENDATIONS – RANGE ROAD

Based upon the conditions encountered and our observations, the roadway section of Range Road lacks adequate base/subgrade structure to support current and future traffic loading. Expansive subgrade material adjacent to weathered bedrock also creates variable subgrade conditions which may account for some of the differences in pavement condition. With a few exceptions, there is no aggregate base beneath the existing asphalt concrete, and most of the AC sections are, by most standards, too thin for surface rehabilitation.

Based upon the conditions encountered and our observations, the pavement failure of the roadway surface appears to be due to poor drainage and age. To address these failures, we recommend reconstruction or heavy rehabilitation of the roadway. Reconstruction has numerous advantages, including addressing underlying subgrade failures and creating the opportunity to correct grading and drainage problems, as well as to properly construct a roadway reasonable design life which will also decrease long‐term costs if properly maintained. Based upon discussions with the client, chemical stabilization/full depth recycling is a possibility for rehabilitation of the roadway. Since the roadway has minimal edge constraints and the road profile will be corrected for poor drainage, it may be feasible for the roadway to be pulverized/graded without hauling off any excess material. If removing material is necessary, the roadway should be pulverized first, graded for material removal, and then processed and graded.

Based upon the encountered native material and existing AC, we believe reconstruction/rehabilitation could be accomplished with a few different options.

One option is to pulverize and lime treat the existing roadway and then place aggregate base and

HMA. Because the encountered native soils are expansive and there is very minimal existing base, this option would result in native material less prone to expansion and contraction, and would also reduce the required aggregate base section. After pulverization and lime treatment, the roadway should be graded to facilitate proper drainage and Class 2 aggregate base should be placed and compacted on top. Based upon laboratory testing, we recommend using 5% lime by dry weight of material and pulverizing to a depth of 15 inches. After finish base grade is made, HMA should be placed on the surface. The HMA thicknesses should be the same as listed in Table 4 below. However, the aggregate base thickness may be reduced by 25 percent.

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A second option is to pulverize, perform both lime treatment and cement treatment of the existing roadway, and then to place HMA on the surface. Lime treatment would help to address problems caused by the native expansive soils, and subsequent cement treatment, also known as full depth reclamation with cement (FDR‐C), would replace the Class 2 aggregate base. After cement treatment is complete, HMA should be placed on the surface of the roadway. Based upon laboratory testing performed on native material, we recommend using 2% lime by dry weight of material processed to a depth of 15 inches. The lime treated material should be allowed to “mellow” for a minimum of 72 hours prior to cement treatment. Cement treatment should then be performed following lime treatment using 2% cement by dry weight of material. The HMA thicknesses should be the same as listed in Table 4 below.

A final option is to reconstruct the roadway using conventional reconstruction methods. This would involve removing the existing roadway to subgrade depth and scarifying and recompacting the material to 95% of maximum dry density. Class 2 aggregate base should then be placed and compacted to 95% of maximum dry density in lifts not exceeding 6 inches. Finally, hot mix asphalt should be placed and compacted on the surface.

Traditional reconstruction sections for various Traffic Indexes can be found below in Table 4.

Calculations have been made using an R‐value of 3.

Traffic Index HMA Section (inches) Base Section (inches)

7.0 4.00 16.00

8.0 4.50 19.00

9.0 5.25 21.50

10.0 6.00 24.00 Table 4: Reconstruction sections based upon an R‐value of 3

Based upon discussions with the client and project owner, we understand that a T.I. of 10.0 is preferred. Where indicated, Class 2 aggregate base should conform to Section 26 of the 2018 Caltrans

Standard Specifications, and HMA should conform to Section 39 of the 2018 Caltrans Standard

Specifications, and should be compacted to a relative density between 92% and 97% of theoretical maximum density. Should lime treatment be chosen, it should conform to Section 24 of the 2018

Caltrans Standard Specifications, and cement treatment, or FDR‐C, should conform to Section 30 of the 2018 Caltrans Standard Specifications.

EXISTING CONDITIONS + FIELD INVESTIGATION – FILL SLOPE ON RANGE ROAD

One drainage area on Range Road is planned for reconstruction. As we understand, in order to construct the new culvert properly, the associated slope and (potentially) roadway will also be

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305727‐001 9 2308‐043.RPT

reconstructed. The roadway across this drainage is very narrow, with a steep slope to the south off the shoulder. One boring was drilled in the area to an approximate depth of 20 feet below ground surface using a Mobile Model B‐53 drill rig equipped with a 6‐inch outside diameter hollow stem auger and an automatic trip hammer for sampling.

Soils encountered in the boring were categorized and logged in general accordance with the Unified

Soil Classification System and ASTM D2488‐17. Copies of the boring logs and a Boring Log Legend are included in Appendix A. In reviewing the boring log and legend, the reader should recognize that the legend is intended as a guideline only, and there are a number of conditions that may influence the soil characteristics as observed during drilling. These include, but are not limited to, the presence of cobbles or boulders, cementation, variations in soil moisture, presence of groundwater, and other factors. Consequently, the logger must exercise judgment in interpreting the subsurface characteristics, possibly resulting in descriptions that vary somewhat from the legend. The reader should also consider the sampler type used when reviewing the blow counts. As the borings were drilled, soil samples were obtained using a ring‐lined barrel sampler (ASTM D3550 ‐17, with shoe similar to D2937‐17) and Standard Penetration Tests (SPT) were conducted at selected depths within the boring (ASTM D1586‐18). Bulk soil samples were also obtained from the auger cuttings.

One ring sample was tested for bulk density per ASTM D2937‐17 (modified for ring liners) and moisture content (ASTM D2216‐19), and one bulk sample was tested for maximum density and optimum moisture content (ASTM D1557‐12). Direct shear tests (ASTM D3080‐11) were conducted on two bulk samples after they were remolded to approximately 90 percent of maximum dry density.

We understand that the planned fill slope will be placed upon an existing slope which exceeds 20 percent. Therefore, we recommend that a keyway should be constructed beneath the toe of the fill.

The keyway should be a minimum of 12 feet wide and should penetrate a minimum of 2 feet into firm, native soils or bedrock. We anticipate that the first foot of native material will be loose topsoil material, which would not be considered firm soil during excavation of the keyway. The bottom of the keyway should be scarified, moisture conditioned, and recompacted prior to being filled with moisture conditioned and properly compacted fill. Then, a series of benches, with a 2 to 3 percent gradient into the slope should be cut into firm soil or bedrock. Each bench should be a minimum of

12 feet in width; the benches may step up the slope as necessary to follow the site contours. The benches should be scarified, moisture conditioned, and recompacted prior to being filled with moisture conditioned and properly compacted fill. Fill should consist of site soils or similar imported material having a minimum strength parameters of 300 psf cohesion and peak shear angle of 30 degrees. If slopes steeper than 2:1 (Horizontal:Vertical) are desired, layers of geogrid should be added to the slope. The geogrid should start at the toe with a layer of Miragrid 7XT, or equivalent.

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This layer should extend from the slope face into the slope a minimum of 15 feet and additional layers should be installed every 4 feet. An alternating layer of Miragrid 2XT should start 2 feet above the first geogrid layer and extend into the face a minimum of 5 feet with additional layers every 4 feet.

Based upon the encountered native soil conditions, back drains should be installed in keyways and on benches per the recommendation of the soils engineer and should, at a minimum, be installed in the keyway and alternating benches thereafter. The drains should consist of either prefabricated geo‐ composite drain panels or a perforated pipe encased in clean free‐draining gravel, which is in turn wrapped in a filter fabric. Geo‐composite drains should comply with Caltrans Standard Specification

96‐1.02C. Details of the fill slopes up to 2:1 and steepened slopes up to 1:1; as well as back drains are attached to this report.

General Recommendations

1. Wherever a new subgrade is established, the subgrade should be scarified a minimum of 8 inches, moisture conditioned to, or just above, optimum moisture content, and compacted.

The subgrade and all aggregate base should be compacted to a minimum of 95 percent of maximum dry density. Subgrade and aggregate base should be firm and unyielding when proofrolled with heavy, rubber‐tire grading equipment prior to continuing construction.

2. Any pavement reinforcement fabrics should be placed per the manufacturer’s recommendations.

3. Finished pavement surfaces should be sloped to freely drain toward appropriate drainage facilities. Water should not be allowed to stand or pond on or adjacent to pavement or other improvements as it could infiltrate into the aggregate base and/or subgrade, causing premature pavement deterioration.

4. To reduce migration of surface drainage into the subgrade, maintenance of pavement areas is critical. Any cracks that develop in the pavement should be promptly sealed.

5. A program of slurry sealing of the new pavement should be established, based upon a maintenance program. Typically, approximate 5‐year increments are considered to be appropriate for application of slurry seals.

6. Where free pavement edges are not constrained, asphalt or concrete curbs should be installed along the edge of the roadway. Curbs should be deepened to maintain a minimum setback distance of 5 feet from the outermost face of the curb to the face of any existing descending slope.

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7. To reduce the potential for undermining of pavement sections, rodent activity should be aggressively controlled.

8. Where fill will be placed on ground that exceeds a 10 percent slope, the prepared soil surfaces should be cut into a flat bench in firm soil or bedrock, or a series of flat benches, with a 2 to

3 percent gradient into the slope. Each bench should be a minimum of 10 feet in width; the benches may step up the slope as necessary to follow the site contours. The benches should be scarified, moisture conditioned, and recompacted prior to being filled with moisture conditioned and properly compacted fill.

9. Where fill will be placed on ground that exceeds a 20 percent slope, in addition to the benches described above; a keyway should be constructed beneath the toe of the fill. The keyway should be a minimum of 12 feet wide and should penetrate a minimum of 2 feet into firm, undisturbed soils or bedrock. The bottom of the keyway should be scarified, moisture conditioned, and recompacted prior to being filled with moisture conditioned and properly compacted fill.

10. Back drains should be installed in keyways and on benches. The drains should consist of either pre‐fabricated geo‐composite drain panels or a perforated pipe encased in clean free‐draining gravel, which is in turn wrapped in a filter fabric. Geo‐composite drains should comply with

Standard Specification 96‐1.02C

We appreciate the opportunity to have provided services for this project and look forward to working with you again in the future. If there are any questions concerning this report, please do not hesitate to contact us.

Sincerely, Earth Systems Pacific

Robert Down, PE Principal Engineer

Attachments: Site Vicinity Map, Exploration Location Map and Boring Log Legend, Boring Logs (28 pages)

Doc. No.:

Laboratory Test Results (6 pages) Keyway and Benching Detail (3 pages)

2308‐043.RPT/pm

4378 Old Santa Fe Road, San Luis Obispo, CA 93401 www.earthsystems.com

(805) 544-3276 Fax (805) 544-1786

Date

January 2023

Project No.

305727-001

Figure 1

SITE VICINITY MAP

Camp San Luis Obispo

Range Roads Rehabilitation

San Luis Obispo County, California

NOT TO SCALE

BASE MAP PROVIDED BY: Google Earth (2023)

SITE

NOT TO SCALE

4378 Old Santa Fe Road, San Luis Obispo, CA 93401 www.earthsystems.com

(805) 544-3276 Fax (805) 544-1786

Date

January 2023

Project No.

305727-001

Figure 2

EXPLORATION LOCATION MAP

Camp San Luis Obispo

Range Roads Rehabilitation

San Luis Obispo County, California

BASE MAP PROVIDED BY: Google Earth (2023)

LEGEND

Boring Location (Approx.)

SB1

SB1

SB2

SB3

SB4

SB5

SB6

SB7

SB8

SB9

SB10

RR1

RR2

RR3

RR4

RR5

RR6

RR7

RR8

RR9

RR15

RR14

RR13

RR12

RR11

RR10

Boring Location (Approx.)

RR1

d r a f t i n g m a s t e r s B o r i n g

L o g

L e g e n d d w g

UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D 2487)

OBSERVED MOISTURE CONDITION

DRY SLIGHTLY MOIST MOIST VERY MOIST WET (SATURATED)

TYPICAL BEDROCK HARDNESS

TYPICAL BEDROCK WEATHERING

GRAIN SIZES

CONSISTENCY

D E

P T

H f e e t

U S

C S

L A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.25" ASPHALT CONCRETE / NO BASE

CL

End of Boring @ 5.0'

No subsurface water encountered

Boring No. SB1

JOB NO.: 305727-001

DATE: 11/17/2022

SANDY LEAN CLAY: brown, medium stiff, moist

(Alluvium)

Camp San Luis Obispo

Range Roads Rehabilitation

San Luis Obispo County, California

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.5" ASPHALT CONCRETE / 4.0" AGGREGATE

BASE

CL

End of Boring @ 5.0'

No subsurface water encountered

Boring No. SB2

JOB NO.: 305727-001

DATE: 11/17/2022

SANDY LEAN CLAY: dark brown, medium stiff, moist (Alluvium)

1.0 - 5.0

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

1.5" ASPHALT CONCRETE / NO BASE

CL

End of Boring @ 5.0'

No subsurface water encountered

Boring No. SB3

JOB NO.: 305727-001

DATE: 11/17/2022

SANDY LEAN CLAY: brown, medium stiff, slightly moist, roots (Alluvium)

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.75" ASPHALT CONCRETE / NO BASE

CL

End of Boring @ 5.0'

No subsurface water encountered

Boring No. SB4

JOB NO.: 305727-001

DATE: 11/17/2022

SANDY LEAN CLAY: dark brown, medium stiff, moist (Alluvium)

1.0 - 5.0

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

3.25" ASPHALT CONCRETE / NO BASE

CH

End of Boring @ 5.0'

No subsurface water encountered

Boring No. SB5

JOB NO.: 305727-001

DATE: 11/17/2022

FAT CLAY WITH SAND: dark brown, stiff, very moist (Alluvium)

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

3.5" ASPHALT CONCRETE / NO BASE

CH

End of Boring @ 5.0'

No subsurface water encountered

Boring No. SB6

JOB NO.: 305727-001

DATE: 11/17/2022

FAT CLAY WITH SAND: black, stiff, very moist

(Alluvium)

1.0 - 5.0

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.0" ASPHALT CONCRETE / NO BASE

CH

End of Boring @ 5.0'

No subsurface water encountered

Boring No. SB7

JOB NO.: 305727-001

DATE: 11/17/2022

FAT CLAY WITH SAND: black, soft, very moist

(Alluvium)

1.0 - 5.0

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

1.5" ASPHALT CONCRETE / NO BASE

CH

End of Boring @ 5.0'

No subsurface water encountered

Boring No. SB8

JOB NO.: 305727-001

DATE: 11/17/2022

FAT CLAY WITH SAND: black, soft, very moist

(Alluvium)

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

1.5" ASPHALT CONCRETE / NO BASE

End of Boring @ 5.0'

No subsurface water encountered

Boring No. SB9

JOB NO.: 305727-001

DATE: 11/17/2022

METAVOLCANIC ROCK: dark olive brown, very soft, moist, moderately weathered (Franciscan

Formation)

1.0 - 5.0

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.75" ASPHALT CONCRETE / NO BASE

CL

End of Boring @ 5.0'

No subsurface water encountered

Boring No. SB10

JOB NO.: 305727-001

DATE: 11/17/2022

SANDY LEAN CLAY: brown, medium stiff, moist

(Alluvium)

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.25" ASPHALT CONCRETE / NO BASE

CL

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR1

JOB NO.: 305727-001

DATE: 11/30/2022

SANDY LEAN CLAY: brown, soft, very moist

(Alluvium)

1.0 - 5.0

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.25" ASPHALT CONCRETE / NO BASE

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR2

JOB NO.: 305727-001

DATE: 11/30/2022

METAVOLCANIC ROCK: olive brown, very soft, moist, intensely weathered (Franciscan

Formation)

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.0" ASPHALT CONCRETE / NO BASE

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR3

JOB NO.: 305727-001

DATE: 11/30/2022

METAVOLCANIC ROCK: olive brown, very soft, moist, decomposed (Franciscan Formation)

1.0 - 5.0

Camp San Luis Obispo

Range Roads Rehabilitation

San Luis Obispo County, California

SANDY LEAN CLAY: brown, stiff, very moist

(Alluvium)

CL

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

3.0" ASPHALT CONCRETE / NO BASE

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR4

JOB NO.: 305727-001

DATE: 11/30/2022

METAVOLCANIC ROCK: olive brown, very soft, moist, decomposed (Franciscan Formation)

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

1.75" ASPHALT CONCRETE / NO BASE

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR5

JOB NO.: 305727-001

DATE: 11/30/2022

METAVOLCANIC ROCK: olive brown, soft, moist, intensely weathered (Franciscan Formation)

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.25" ASPHALT CONCRETE / NO BASE

CH

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR6

JOB NO.: 305727-001

DATE: 11/30/2022

FAT CLAY WITH SAND: black, soft, very moist

(Alluvium)

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.25" ASPHALT CONCRETE / NO BASE

5.0 - 6.5

10.0 - 10.5

15.0 - 16.0 50/2"

50/4"

20.0 - 21.5

50/1"

CL

SC

CLAYEY SAND WITH GRAVEL: pale brown, loose, slightly moist

End of Boring @ 20.5'

No subsurface water encountered

Boring No. RR7

JOB NO.: 305727-001

DATE: 11/17/2022

SANDY LEAN CLAY: brown, medium stiff, moist, trace gravel (Fill)

2.0 - 3.0

Camp San Luis Obispo

Range Roads Rehabilitation

San Luis Obispo County, California

FAT CLAY WITH SAND: black, soft, very moist

METAVOLCANIC ROCK: mottled olive brown to pale brown to yellowish brown, soft, slightly moist, moderately weathered (Franciscan Melange) moderately hard

CH

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.0" ASPHALT CONCRETE / 1" AGGREGATE

BASE/ 3.0" OLD ASPHALT CONCRETE

SC

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR8

JOB NO.: 305727-001

DATE: 11/30/2022

CLAYEY SAND WITH GRAVEL: reddish brown to brown, medium dense, moist (Fill)

1.0 - 5.0

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.0" ASPHALT CONCRETE / NO BASE

SC

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR9

JOB NO.: 305727-001

DATE: 11/30/2022

CLAYEY SAND WITH GRAVEL: reddish brown to brown, medium dense, moist (Fill)

1.0 - 5.0

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

1.5" ASPHALT CONCRETE / 1.25" AGGREGATE

BASE/ 4.5" OLD ASPHALT CONCRETE

SC

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR10

JOB NO.: 305727-001

DATE: 11/30/2022

SANDY LEAN CLAY: brown, soft, moist (Alluvium)

1.0 - 5.0

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

3.0" ASPHALT CONCRETE / NO BASE

SC

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR11

JOB NO.: 305727-001

DATE: 11/30/2022

METAVOLCANIC ROC: olive brown, very soft, moist, intensely weathered (Franciscan Melange)

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.25" ASPHALT CONCRETE / NO BASE

SC

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR11

JOB NO.: 305727-001

DATE: 11/30/2022

CLAYEY SAND WITH GRAVEL: reddish brown, medium dense moist (Fill)

Camp San Luis Obispo

Range Roads Rehabilitation light brown

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

1.25" ASPHALT CONCRETE / NO BASE

SC

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR13

JOB NO.: 305727-001

DATE: 11/30/2022

CLAYEY SAND WITH GRAVEL: reddish brown, medium dense, moist (Fill)

Camp San Luis Obispo

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

2.0" ASPHALT CONCRETE / NO BASE

SC

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR14

JOB NO.: 305727-001

DATE: 11/30/2022

CLAYEY SAND WITH GRAVEL: brown, medium dense moist (Fill)

Camp San Luis Obispo

Range Roads Rehabilitation

San Luis Obispo County, California

FAT CLAY: black, very soft, very moist

CH

P T

H f e e t

U S

A

S S

S Y

M B

O L

I N

T E

R V

A L f e e t

S A

M P

L E

T Y

P E

D R

Y

D

E N

S I T

Y p c f

M O

I S

T U

R E

B L O

W S

P E

R

I N

SAMPLE DATA

SOIL DESCRIPTION

LEGEND: Ring Sample Grab Sample Shelby Tube Sample SPT

NOTE: This log of subsurface conditions is a simplification of actual conditions encountered. It applies at the location and time of drilling.

Subsurface conditions may differ at other locations and times.

AUGER TYPE: 6" Hollow Stem

DRILL RIG: Mobile B-53 with Automatic Hammer

LOGGED BY: S. Hemmer

3.0" ASPHALT CONCRETE / NO BASE

CH

End of Boring @ 5.0'

No subsurface water encountered

Boring No. RR15

JOB NO.: 305727-001

DATE: 11/30/2022

FAT CLAY: grayish brown, soft, moist (Alluvium)

1.0 - 5.0

Camp San Luis Obispo

Camp SLO Range Road Repair 305727-001

RESISTANCE 'R ' VALUE AND EXPANSION PRESSURE ASTM D 2844/D2844M-18

December 28, 2022

SB4 @ 1.0 -5.0' Dry Density @ 300 psi Exudation Pressure: N/A Dark Brown Sandy Fat Clay (CH) %Moisture @ 300 psi Exudation Pressure: N/A

R-Value - Exudation Pressure: N/A R-Value - Expansion Pressure: N/A

R-Value @ Equilibrium: Less than 5 (sample extruded from mold during testing)

0100200300400500600700800

R -V

A L

U E

EXUDATION PRESSURE, psi

EXUDATION PRESSURE

CHART

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

C O

V E

R T

H

IC

K N

E

SS

B Y

E X

U D

A T

IO

N

P R

E

SS

U R

E , f t

COVER THICKNESS BY EXPANSION PRESSURE, ft

EXPANSION PRESSURE CHART

December 28, 2022

SB6 @ 1.0 -5.0' Dry Density @ 300 psi Exudation Pressure: N/A Black Fat Clay with Sand (CH) %Moisture @ 300 psi Exudation Pressure: N/A

R-Value - Exudation Pressure: N/A R-Value - Expansion Pressure: N/A

R-Value @ Equilibrium: Less than 5 (sample extruded from mold during testing)

0100200300400500600700800

R -V

A L

U E

EXUDATION PRESSURE, psi

EXUDATION PRESSURE

CHART

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

C O

V E

R T

H

IC

K N

E

SS

B Y

E X

U D

A T

IO

N

P R

E

SS

U R

E , f t

December 28, 2022

RR3 @ 1.0 -5.0' Dry Density @ 300 psi Exudation Pressure: 110.2-pcf Brown Sandy Lean Clay (CL) %Moisture @ 300 psi Exudation Pressure: 20.1% Specified Traffic Index: 5.0 R-Value - Exudation Pressure: 12

R-Value - Expansion Pressure: 7 R-Value @ Equilibrium: 7

0100200300400500600700800

R -V

A L

U E

EXUDATION PRESSURE, psi

EXUDATION PRESSURE

CHART

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

C O

V E

R T

H

IC

K N

E

SS

B Y

E X

U D

A T

IO

N

P R

E

SS

U R

E , f t

December 28, 2022

RR7 @ 1.0 -5.0' Dry Density @ 300 psi Exudation Pressure: 112.6-pcf Brown Sandy Lean Clay (CL) %Moisture @ 300 psi Exudation Pressure: 17.1% Specified Traffic Index: 5.0 R-Value - Exudation Pressure: 10

R-Value - Expansion Pressure: 3 R-Value @ Equilibrium: 3

0100200300400500600700800

R -V

A L

U E

EXUDATION PRESSURE, psi

EXUDATION PRESSURE

CHART

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

C O

V E

R T

H

IC

K N

E

SS

B Y

E X

U D

A T

IO

N

P R

E

SS

U R

E , f t

December 28, 2022

RR8 @ 1.0 -5.0' Dry Density @ 300 psi Exudation Pressure: 115.8-pcf Reddish Brown Clayey Sand with Gravel (SC) %Moisture @ 300 psi Exudation Pressure: 15.3% Specified Traffic Index: 5.0 R-Value - Exudation Pressure: 23

R-Value - Expansion Pressure: 11 R-Value @ Equilibrium: 11

0100200300400500600700800

R -V

A L

U E

EXUDATION PRESSURE, psi

EXUDATION PRESSURE

CHART

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6

C O

V E

R T

H

IC

K N

E

SS

B Y

E X

U D

A T

IO

N

P R

E

SS

U R

E , f t

December 28, 2022

RR15 @ 1.0 -5.0' Dry Density @ 300 psi Exudation Pressure: N/A Grayish Brown Fat Clay (CH) %Moisture @ 300 psi Exudation Pressure: N/A

R-Value - Exudation Pressure: N/A R-Value - Expansion Pressure: N/A

R-Value @ Equilibrium: Less than 5 (sample extruded from mold during testing)

0100200300400500600700800

R -V

A L

U E

EXUDATION PRESSURE, psi

EXUDATION PRESSURE

CHART

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6

C O

V E

R T

H

IC

K N

E

SS

B Y

E X

U D

A T

IO

N

P R

E

SS

U R

E , f t

-3 ty p

12' min.

Typical

Bench back drains, as recommended by

Geotechnical Engineer/ Geologist during construction

Compacted Fill

Maximum Slope; 2:1 unless otherwise recommended by Geotechnical

Engineer/ Geologist

Depth to be determined in field by

Geotechnical Engineer/ Geologist

Natural Slope

Toe of Slope

Loose or Soft

Soil

Back drain as recommended by

Geotechnical Engineer

2' Min.

Firm Soil/

Bedrock

Firm Soil/

Bedrock

SCHEMATIC ONLY

NOT TO SCALE

4378 Old Santa Fe Road, San Luis Obispo, CA 93401 www.earthsystems.com

(805) 544-3276 Fax (805) 544-1786

TYPICAL BENCH AND KEYWAY DETAIL

Camp San Luis Obispo Range Roads

San Luis Obispo, California

Date

August 2023

Project No.

305727-001

-3 ty p

12' min.

Typical

Bench back drains, as recommended by

Geotechnical Engineer/ Geologist during construction

Compacted Fill

Maximum Slope; 2:1 unless otherwise recommended by Geotechnical

Engineer/…